DE102023112151A1 - INJECTION MOLDING MACHINE AND CONTROL DEVICE OF INJECTION MOLDING MACHINE - Google Patents

Abstract

A technique capable of easily and appropriately adjusting a cold start prevention period for limiting operation of a plasticizing member is provided. An injection molding machine (10) includes: a cylinder (310) holding a molding material to be injected into a mold; a plasticizing member provided in the cylinder (310) so as to be movable and rotatable; a temperature measuring device (314) that measures a temperature of the cylinder (310) or the mold; and a period setting unit (715) configured to set a cold start prevention period, which is a period for limiting the injection of the molding material into the mold, based on the temperature measured by the temperature measuring device (314) until a temperature of the Molding material or the temperature of the mold increases. The period setting unit (715) stores temperature-time data (TD) in which the temperature measured by the temperature measuring device (314) is associated with time, and adjusts cold start prevention period based on an actual temperature (Tz) of the stored temperature-time -Data (TD).

Description

BACKGROUND OF THE INVENTION

Field of invention

The present disclosure relates to an injection molding machine and a control device of an injection molding machine.

Description of the prior art

In an injection molding machine, a plurality of temperature gauges are provided in a cylinder, and a temperature of the cylinder is increased based on a temperature detected by each temperature gauge. However, when the injection molding machine is started, a temperature of a molding material in the cylinder does not reach the set temperature even if the temperature reaches a set temperature of a heater. If a screw or the like is moved in a state in which the temperature of the molding material is not sufficiently increased, an excessive load may be applied to a plasticizing member such as the screw, and damage or the like may be caused. In addition, when the molding material is injected from the injection molding machine into a mold in a state in which the temperature is not sufficiently elevated, there is a possibility that the mold has a poor filling condition, for example, that the mold is eaten, a molded product does not come out of the mold or create burrs. Particularly, in a case where the injection molding machine performs thermal curing (reaction molding), there are problems in that the molding material does not solidify normally, functional performance required for the molded product cannot be obtained, and the like.

Therefore, the injection molding machine sets a period (cold start prevention period) of waiting until the temperature of the molding material rises sufficiently and performs lockup to limit operation of the plasticizing member during the cold start prevention period.

However, in a situation where an operation of the injection molding machine is temporarily stopped and then immediately restarted due to a power failure, an operation error or the like, the temperature of the molding material or mold is high, and there are cases where there is a risk of damage Components are low. Even in this case, if the operation of the device is waited for an initially set cold start prevention period, it takes time to restart the device. Therefore, Japanese Unexamined Patent Publication No. H11-170327 an injection molding machine in which, when a time after stopping an operation of the injection molding machine is equal to or shorter than a predetermined time, the operation of the injection molding machine is permitted based on a resin type and a stopping time from stopping molding to restarting.

SUMMARY OF THE INVENTION

As described in Japanese Unexamined Patent Publication No. H11-170327 described, however, in a case of control according to resin type, a complicated calculation program must be prepared in accordance with resin properties, and a special electrical component for executing the calculation program is required. Furthermore, resin information (e.g. shear force, viscosity or pvT properties) must be entered before operating the injection molding machine, resulting in an increased workload for an operator. In particular, depending on the injection molding machine, it is necessary for the operator to input the resin information every time the resin is changed, which puts a great burden on the operator.

According to an embodiment of the present invention, a technique capable of easily and appropriately adjusting a cold start prevention period for limiting operation of a plasticizing member is provided.

An injection molding machine according to an aspect of the present invention includes: a cylinder that holds a molding material to be injected into a mold; a plasticizing member provided in the cylinder so as to be movable and rotatable; a temperature measuring device that measures a temperature of the cylinder or mold; and a period setting unit configured to set a cold start prevention period, which is a period for limiting an operation of the plasticizing member until a temperature of the molding material or the temperature of the mold increases, the period setting unit storing temperature-time data, in which the temperature measured by the temperature measuring device is linked to time, and sets the cold start prevention period based on an actual temperature of the stored temperature-time data.

A control device of an injection molding machine according to another aspect of the present invention enables a temperature measuring device to measure a temperature of a cylinder holding a molding material to be injected into a mold or a temperature of the mold, and allows a temperature control mechanism to adjust the temperature of the cylinder or mold based on the temperature measured by the temperature measuring device, the control device including: a period setting unit configured to set a cold start prevention period, which is a period for limiting an operation a plasticizing element provided in the cylinder so as to be movable and rotatable until a temperature of the molding material or the temperature of the mold increases, the period setting unit storing temperature-time data in which the temperature measured by the temperature measuring device is included Time is linked, and sets the cold start prevention period based on an actual temperature of the stored temperature-time data.

The injection molding machine and the control device of an injection molding machine according to the aspects of the present invention can easily and appropriately adjust the cold start prevention period for limiting the operation of the plasticizing member.

BRIEF DESCRIPTION OF THE FIGURES

• 1 is a view showing a state in which mold opening is completed in an injection molding machine according to an embodiment.
• 2 is a view showing a state in which mold closing/clamping is performed in the injection molding machine according to the embodiment.
• 3 is a functional block diagram showing an example of components of a control device.
• 4 is a diagram showing an example of processes of a molding cycle.
• 5 is a diagram showing an example of temperature-time data stored in a storage medium.
• 6 is a flowchart showing a processing flow for setting a cold start prevention period.
• 7 is a diagram showing a decision table of a trip condition in a heater selection control.
• 8A and 8B are diagrams for describing interpolation of temperature-time data.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments for carrying out the present disclosure will be described below with reference to the drawings. In each drawing, there are cases where like elements are denoted by like reference numerals, and overlapping descriptions may be omitted.

(injection molding machine)

1 is a view showing a state in which mold opening is completed in an injection molding machine according to an embodiment. 2 is a view showing a state in which mold closing/clamping is performed in the injection molding machine according to the embodiment. In the present description, an X-axis direction, a Y-axis direction, and a Z-axis direction are perpendicular to each other. The X-axis direction and the Y-axis direction represent a horizontal direction, and the Z-axis direction represents a vertical direction. In a case where a mold clamping/clamping unit 100 is of a horizontal type, the X-axis direction represents an opening - and closing direction of the mold, and the Y-axis direction represents a width direction of an injection molding machine 10. A negative side in the Y-axis direction is called an operating side, and a positive side in the Y-axis direction is called a counter-operating side.

As in 1 and 2 As shown, the injection molding machine 10 includes the mold closing/clamping unit 100 that opens and closes a mold unit 800, an ejector unit 200 that ejects a molded product molded by the mold unit 800, an injection unit 300 that injects a mold material into the mold unit 800, a moving unit 400 that causes the injection unit 300 to move back and forth with respect to the molding unit 800, a control device 700 that controls each component of the injection molding machine 10, and a frame 900 that supports each component of the injection molding machine 10. The frame 900 includes a mold clamping/clamping unit frame 910 that supports the mold clamping/clamping unit 100 and an injection unit frame 920 that supports the injection unit 300. The mold closing/clamping unit frame 910 and the injection unit frame 920 are each installed on a floor 2 via a height adjuster 930. The control device 700 is arranged in an interior of the injection unit frame 920. Each component of the injection molding machine 10 will be described below.

(mold closing/clamping unit)

In describing the mold clamping/clamping unit 100, a moving direction of a movable plate 120 during mold closing (for example, a positive direction of an axis) is defined as backwards.

The mold closing/clamping unit 100 performs mold closing, pressurizing, mold closing/clamping, pressure releasing, and mold opening of the mold unit 800. The mold unit 800 includes a stationary mold 810 and a movable mold 820.

For example, the mold clamping/clamping unit 100 is of a horizontal type, and the opening and closing direction of the mold is a horizontal direction. The mold clamping/clamping unit 100 includes a stationary plate 110 to which the stationary mold 810 is attached, the movable plate 120 to which the movable mold 820 is attached, and a moving mechanism 102 that moves the movable plate 120 in the opening and closing position Closing direction of the mold moves with respect to the stationary plate 110.

The stationary plate 110 is attached to the mold clamping/clamping unit frame 910. The stationary mold 810 is attached to a surface of the stationary plate 110 facing the movable plate 120.

The movable plate 120 is arranged to be movable in the mold opening and closing directions with respect to the mold clamping/clamping unit frame 910. A guide 101 that guides the movable plate 120 is placed on the mold clamping/clamping unit frame 910. The movable mold 820 is attached to a surface of the movable plate 120 facing the stationary plate 110.

The moving mechanism 102 causes the movable platen 120 to move back and forth with respect to the stationary platen 110 so that mold closing, pressurizing, mold closing/clamping, pressure releasing, and mold opening of the mold unit 800 are performed. The moving mechanism 102 includes a toggle support 130 disposed at a distance from the stationary plate 110, a column 140 connecting the stationary plate 110 and the toggle support 130, a toggle mechanism 150 supporting the movable plate 120 in the opening and opening position Closing direction of the mold moves with respect to the toggle carrier 130, a mold closing/clamping motor 160 that operates the toggle lever mechanism 150, a motion conversion mechanism 170 that converts a rotary motion into a linear motion of the mold closing/clamping motor 160, and a mold space adjustment mechanism 180 that has a Distance between the stationary plate 110 and the toggle lever support 130 adjusts.

The toggle support 130 is arranged at a distance from the stationary plate 110 and is placed on the mold clamping/clamping unit frame 910 so as to be movable in the opening and closing direction of the mold. The toggle support 130 may be arranged to be movable along a guide laid on the mold clamping/clamping unit frame 910. The leadership of the toggle lever carrier 130 can be common to the leadership 101 of the movable plate 120.

In the present embodiment, the stationary plate 110 is fixed to the mold clamping/clamping unit frame 910, and the toggle bracket 130 is arranged to be movable with respect to the mold clamping/clamping unit frame 910 in the mold opening and closing directions . However, the toggle support 130 may be attached to the mold clamping/clamping unit frame 910, and the stationary plate 110 may be arranged to be movable with respect to the mold clamping/clamping unit frame 910 in the mold opening and closing directions.

The column 140 connects the stationary plate 110 and the toggle support 130 to each other at a distance L in the opening and closing directions of the mold. Multiple (e.g. four) columns 140 can be used. The plurality of columns 140 are arranged parallel to each other in the opening and closing directions of the mold and extend in accordance with a mold closing/clamping force. At least one of the columns 140 may be provided with a column strain detector 141 that measures a strain of the column 140. The column strain detector 141 transmits a signal indicating a measurement result thereof to the control device 700. The measurement result of the column strain detector 141 is used for measuring the mold closing/clamping force or the like.

In the present embodiment, as a mold closing/clamping force detector for measuring the mold closing/clamping force, the column strain detector 141 is used. However, the present invention is not limited to this. The mold closing/clamping force detector is not limited to one type of strain gauge. The mold closing/clamping force detector can be of piezoelectric type, capacitive type, hyd a spatial type, an electromagnetic type or the like, and an attachment position thereof is not limited to the column 140.

The toggle mechanism 150 is disposed between the movable plate 120 and the toggle bracket 130 and moves the movable plate 120 with respect to the toggle bracket 130 in the mold opening and closing directions. The toggle mechanism 150 includes a crosshead 151 that moves in the opening and closing directions of the mold, and a pair of link groups that are flexed and stretched by movement of the crosshead 151. Each pair of link groups has a first link 152 and a second link 153 connected to be freely flexed and stretched by a pin or the like. The first link 152 is oscillatingly attached to the movable plate 120 by a pin or the like. The second link 153 is oscillatingly attached to the toggle lever support 130 by a pin or the like. The second link 153 is attached to the crosshead 151 via a third link 154. When the crosshead 151 is caused to move back and forth with respect to the toggle bracket 130, the first link 152 and the second link 153 are flexed and extended, and the movable plate 120 moves forward with respect to the toggle bracket 130. and backwards.

A configuration of the toggle mechanism 150 is not limited to configurations shown in 1 and 2 are shown. In 1 and 2 For example, the number of nodes in each link group is five, but can be four. An end portion of the third link 154 may be connected to the node between the first link 152 and the second link 153.

The mold clamping/clamping motor 160 is attached to the toggle bracket 130 and actuates the toggle mechanism 150. The mold clamping/clamping motor 160 causes the crosshead 151 to move back and forth with respect to the toggle bracket 130 so that the first link 152 and the second link 153 is flexed and extended and the movable plate 120 moves back and forth with respect to the toggle support 130. The mold clamping/clamping motor 160 is directly connected to the motion conversion mechanism 170, but may be connected to the motion conversion mechanism 170 via a belt, a pulley, or the like.

The motion conversion mechanism 170 converts a rotary motion of the mold closing/clamping motor 160 into a linear motion of the crosshead 151. The motion conversion mechanism 170 includes a spindle shaft and a spindle nut screwed onto the spindle shaft. A ball or a roller can be inserted between the spindle shaft and the spindle nut.

The mold closing/clamping unit 100 performs a mold closing process, a pressurizing process, a mold closing/clamping process, a pressure relief process, a mold opening process, and the like under the control of the controller 700.

In the mold closing process, the mold clamping/clamping motor 160 is driven to cause the crosshead 151 to move forward at a set moving speed to a mold closing completion position, thereby causing the movable platen 120 to move forward so that the movable mold 820 touches the stationary form 810. For example, a position or a moving speed of the crosshead 151 is measured by using a mold clamping/clamping motor encoder 161. The mold closing/clamping motor encoder 161 measures rotation of the mold closing/clamping motor 160 and transmits a signal indicating a measurement result thereof to the controller 700.

A crosshead position detector for measuring a position of the crosshead 151 and a crosshead moving speed detector for measuring a moving speed of the crosshead 151 are not limited to the mold closing/clamping motor encoder 161, and a general detector may be used. Furthermore, a movable platen position detector for measuring a position of the movable platen 120 and a moving platen moving speed detector for measuring a moving speed of the movable platen 120 are not limited to the mold clamping/clamping motor encoder 161, and a general detector can be used.

In the pressurizing process, the mold closing/clamping motor 160 is further driven to cause the crosshead 151 to further move forward from the mold closing finishing position to a mold closing/clamping position, thereby generating a mold closing/clamping force.

In the mold closing/clamping process, the mold closing/clamping motor 160 is driven to maintain the position of the crosshead 151 at the mold closing/clamping position. In the mold closing/clamping process, the mold closing/clamping process generated during the pressurization process is maintain clamping force. In the mold closing/clamping process there is a cavity space 801 (see 2 ) between the movable mold 820 and the stationary mold 810, and the injection unit 300 fills the cavity space 801 with a liquid mold material. A molded product is obtained by solidifying the molding material filled therein.

The number of cavity spaces 801 can be one or more. In the latter case, several of the molded products can be obtained at the same time. A feed material may be disposed in one portion of the cavity space 801, and the other portion of the cavity space 801 may be filled with the molding material. A molded product in which the feedstock and the molding material are integrated with each other can be obtained.

In the pressure relief process, the mold closing/clamping motor 160 is driven to cause the crosshead 151 to move backward from the mold closing/clamping position to a mold opening start position, so that the movable plate 120 moves backward to meet the mold closing/clamping force to reduce. The mold opening start position and the mold closing completion position may be the same position.

In the mold opening process, the mold closing/clamping motor 160 is driven to cause the crosshead 151 to move backward at a set moving speed from the mold opening start position to a mold opening completion position, so that the movable plate 120 moves backward and the movable mold 820 is separated from the stationary form 810. Thereafter, the ejector unit 200 ejects the molded product from the movable mold 820.

Setting conditions in the mold closing process, the pressurizing process and the mold closing/clamping process are collectively set as a series of setting conditions. For example, the moving speed or positions (including a mold closing start position, a moving speed switching position, the mold closing completion position, and the mold closing/clamping position) of the crosshead 151 and the mold closing/clamping force in the mold closing process and in the pressurizing process are collectively set as a set of setting conditions set. The mold-closing start position, the moving speed switching position, the mold-closing completion position, and the mold-closing/clamping position are arranged in this order from a back to a front, and represent a start point and an end point of a section in which the moving speed is set. The movement speed is set for each section. The number of moving speed switching positions may be one or more. The movement speed switching position may not be set. Either only the mold closing/clamping position or the mold closing/clamping force can be set.

The setting condition in the pressure relief process and the mold opening process are set in the same way. For example, the moving speed or positions (the mold opening start position, the moving speed switching position, and the mold opening completion position) of the crosshead 151 in the pressure relief process and the mold opening process are collectively adjusted as a series of setting conditions. The mold opening start position, the moving speed switching position and the mold opening finishing position are arranged in this order from the front to the back and represent the starting point and the end point of the moving speed adjustment section. The movement speed is set for each section. The number of moving speed switching positions may be one or more. The movement speed switching position may not be set. The mold opening start position and the mold closing completion position may be the same position. Furthermore, the mold opening completion position and the mold closing start position may be the same position.

Instead of the moving speed, positions and the like of the crosshead 151, the moving speed, positions and the like of the movable plate 120 may be adjusted. Furthermore, instead of the position (for example, the mold closing/clamping position) of the crosshead or the position of the movable platen, the mold closing/clamping force may be adjusted.

The toggle mechanism 150 amplifies a driving force of the mold closing/clamping motor 160 and transmits the driving force to the movable plate 120. A gain increase is referred to as a toggle increase. The toggle magnification is changed according to an angle θ (hereinafter also referred to as a “link angle θ”) formed between the first link 152 and the second link 153. The link angle θ is obtained from the position of the crosshead 151. When the link angle θ is 180°, the toggle lever extension is maximized.

In a case where a mold space of the mold unit 800 is changed due to replacement of the mold unit 800, a temperature change in the mold unit 800, or the like, mold space adjustment is performed so that a predetermined mold closing/clamping force is obtained during mold closing/clamping becomes. For example, in the mold space adjustment, the distance L between the stationary plate 110 and the toggle support 130 is adjusted so that the link angle θ of the toggle mechanism 150 becomes a predetermined angle at a mold contact time at which the movable mold 820 contacts the stationary mold 810.

The mold closing/clamping unit 100 has the mold space adjustment mechanism 180. The mold space adjustment mechanism 180 performs the mold space adjustment by adjusting the distance L between the stationary platen 110 and the toggle support 130. For example, a time for mold space adjustment is determined from an end point of a molding cycle to a starting point of a subsequent molding cycle. The mold space adjusting mechanism 180 includes, for example, a spindle shaft 181 formed in a rear end portion of the column 140, a spindle nut 182 supported by the toggle bracket 130 so as to be rotatable and unable to move back and forth, and a mold space adjustment motor 183, which rotates the spindle nut 182 screwed onto the spindle shaft 181.

The spindle shaft 181 and the spindle nut 182 are provided for each of the columns 140. A rotational driving force of the mold space adjustment motor 183 can be transmitted to a plurality of the spindle nuts 182 via a rotational driving force transmission unit 185. The multiple spindle nuts 182 can be rotated synchronously with each other. The plurality of spindle nuts 182 can be rotated individually by changing a transmission channel of the rotation driving force transmission unit 185.

The rotary driving force transmission unit 185 is configured to include a gear, for example. In this case, a driven gear is formed on an outer periphery of each spindle nut 182, a driving gear is attached to an output shaft of the mold space adjusting motor 183, and a plurality of intermediate gears meshing with the driven gear and the driving gear are rotatable in a central portion of the Knee lever carrier 130 held. The rotation driving force transmission unit 185 may be configured to include a belt, a pulley, or the like instead of the gear.

Actuation of the mold space adjustment mechanism 180 is controlled by the control device 700. The controller 700 drives the mold space adjustment motor 183 to rotate the spindle nut 182. As a result, a position of the toggle bracket 130 with respect to the column 140 is adjusted, and the distance L between the stationary plate 110 and the toggle bracket 130 is adjusted. In addition, multiple mold space adjustment mechanisms can be used in combination.

The distance L is measured using a shape space matching motor encoder 184. The mold space adjustment motor encoder 184 measures a rotation amount or a rotation direction of the mold space adjustment motor 183 and transmits a signal indicating a measurement result thereof to the controller 700. The measurement result of the mold space adjustment motor encoder 184 is monitored or controlled in position or the distance L of the toggle lever carrier 130 is used. A toggle beam position detector for measuring the position of the toggle beam 130 and a distance detector for measuring the distance L are not limited to the die space adjustment motor encoder 184, and a general detector may be used.

The mold closing/clamping unit 100 may include a mold temperature controller that adjusts the temperature of the mold unit 800. The molding unit 800 has a flow path of a temperature control medium inside. The mold temperature controller adjusts the temperature of the mold unit 800 by adjusting a temperature of the temperature control medium supplied to the flow path of the mold unit 800.

The mold clamping/clamping unit 100 of the present embodiment is of the horizontal type in which the opening and closing direction of the mold is the horizontal direction, but may be of a vertical type in which the opening and closing direction of the mold is up-down -direction is.

The mold clamping/clamping unit 100 of the present embodiment includes the mold clamping/clamping motor 160 as a drive unit. However, instead of the mold closing/clamping motor 160, a hydraulic cylinder can be provided. In addition, the mold closing/clamping unit 100 may include a linear motor for mold opening and closing, and may include an electromagnet for mold closing/clamping.

(ejector unit)

In describing the ejector unit 200, similarly to the description of the mold closing/clamping unit 100, a moving direction of the movable plate 120 during mold closing (for example, the positive direction of the X axis) is defined as forward, and a moving direction of the movable plate 120 during of the mold opening (for example, the negative direction of the X-axis) is defined as backward.

The ejector unit 200 is attached to the movable plate 120 and moves back and forth together with the movable plate 120. The ejector unit 200 includes an ejector bar 210 that ejects a molded product from the mold unit 800, and a drive mechanism 220 that moves the ejector bar 210 in the moving direction (X-axis direction) of the movable plate 120.

The ejector rod 210 is arranged to move back and forth in a through hole of the movable plate 120. A front end portion of the ejector rod 210 comes into contact with an ejector plate 826 of the movable die 820. The front end portion of the ejector rod 210 may be connected to the ejector plate 826 or may not be connected thereto.

The drive mechanism 220 includes, for example, an ejector motor and a motion conversion mechanism that converts a rotary motion of the ejector motor into a linear motion of the ejector rod 210. The motion conversion mechanism includes a spindle shaft and a spindle nut screwed onto the spindle shaft. A ball or a roller can be inserted between the spindle shaft and the spindle nut.

The ejector unit 200 performs an ejection process under the control of the control device 700. In the ejecting process, the ejector rod 210 is caused to move forward from a standby position to an eject position at a set moving speed, so that the ejector plate 826 moves forward to eject the molded product. Thereafter, the ejector motor is driven to cause the ejector rod 210 to move backward at a set moving speed so that the ejector plate 826 moves backward to an original standby position.

For example, a position or a moving speed of the ejector rod 210 is measured by using an ejector motor encoder. The ejector motor encoder measures the rotation of the ejector motor and transmits a signal indicating a measurement result thereof to the controller 700. An ejector bar position detector for measuring the position of the ejector bar 210 and an ejector bar moving speed detector for measuring the moving speed of the ejector bar 210 are not limited to the ejector motor encoder, and a general detector can be used.

(injection unit)

When describing the injection unit 300, unlike the description of the mold closing/clamping unit 100 or the description of the ejector unit 200, a movement direction of a screw 330 during filling (for example, the negative direction of the X-axis) is defined as forward, and a movement direction of the screw 330 during plasticization (e.g., the positive direction of the X-axis) is defined as backward.

The injection unit 300 is installed on a sliding base 301, and the sliding base 301 is arranged to move back and forth with respect to the injection unit frame 920. The injection unit 300 is arranged so that it can move back and forth with respect to the mold unit 800. The injection unit 300 touches the molding unit 800 and fills the cavity space 801 within the molding unit 800 with the molding material. The injection unit 300 includes, for example, a cylinder 310 that heats the molding material, the screw 330 arranged to move back and forth and rotate inside the cylinder 310, a plasticizing motor 340 that rotates the screw 330, an injection motor 350 that causes the screw 330 to move back and forth, and a load detector 360 that measures a load transmitted between the injection motor 350 and the screw 330.

The cylinder 310 includes a cylindrical cylinder body 315 and a funnel-shaped nozzle 320 provided at a front end portion of the cylinder body 315. The cylinder body 315 heats the molding material supplied into the cylinder body 315 through a supply port 311. The molding material contains, for example, a resin. The molding material is formed in a pellet shape, for example, and is supplied to the supply port 311 in a solid state. The supply port 311 is formed in a rear portion of the cylinder body 315. A cooler 312, such as a water cooling cylinder the, is on an outer circumference of the rear portion of the cylinder body 315 intended. The nozzle 320 forms a portion that is pressed against the molding unit 800 to fill the molding unit 800 with the molding material.

Furthermore, in the injection molding machine 10 according to the present embodiment, a plurality of zones are set to independently control heating of the cylinder 310 along an axial direction (X-axis direction) of the cylinder 310. For example, as the plurality of zones, a first zone, a second zone, a third zone and a fourth zone are set in this order from the back to the front in the cylinder body 315. The fourth zone is the front end portion of the cylinder body 315.

The cylinder 310 includes a heating unit 313 (temperature control mechanism) and a temperature measuring device 314 for each of the plurality of zones. Each of the heating units 313 and the temperature measuring devices 314 is provided to be in contact with an outer peripheral surface of the cylinder 310 (or at a position near the outer peripheral surface thereof). As the heating unit 313, for example, a heater such as a heating band that surrounds the outer peripheral surface of the cylinder 310 can be used. The control device 700 controls each of the heating units 313 provided for the corresponding zones to adjust a temperature in the axial direction of the cylinder 310. In terms of control, the controller 700 controls each of the heating units 313 so that a temperature of each of the temperature measuring devices 314 becomes a set temperature set for the corresponding zone.

The screw 330 is arranged so that it can rotate inside the cylinder 310 and move back and forth. As the screw 330 is rotated, the molding material is conveyed forward along a spiral groove of the screw 330. The molding material is gradually melted by heat from the cylinder 310 as it is conveyed forward. When the liquid molding material is conveyed forward in front of the screw 330 and accumulates in a front portion of the cylinder 310, the screw 330 moves backward. Thereafter, when the screw 330 is caused to move forward, the liquid molding material accumulated in front of the screw 330 is injected from the nozzle 320 and fills an interior of the molding unit 800.

As a backflow prevention valve for preventing backflow of the molding material conveyed backward from the front of the screw 330 when the screw 330 is pushed forward, a backflow prevention ring 331 is attached to a front portion of the screw 330 to move back and forth.

The backflow prevention ring 331 is pushed backward by a pressure of the molding material in front of the screw 330 when the screw 330 is caused to move forward, and moves backward relative to the screw 330 to a closed position (see 2 ), in which a flow path of the molding material is closed. Accordingly, the molding material accumulated in front of the screw 330 is prevented from flowing backward.

On the other hand, the backflow prevention ring 331 is pushed forward by the pressure of the molding material fed forward along the spiral groove of the screw 330 when the screw 330 is rotated, and moves forward relative to the screw 330 to an opening position (see 1 ), in which the flow path of the molding material is open. Accordingly, the molding material is conveyed in front of the screw 330.

The backflow prevention ring 331 may be either a co-rotating type that rotates together with the screw 330 or a non-co-rotating type that does not rotate together with the screw 330.

The injection unit 300 may include a drive source that causes the backflow prevention ring 331 to move back and forth with respect to the screw 330 between the opening position and the closing position.

The plasticizing motor 340 rotates the screw 330. The driving source for rotating the screw 330 is not limited to the plasticizing motor 340 and may be, for example, a hydraulic pump.

The injection motor 350 is an injection drive source that causes the screw 330 to move back and forth. A motion conversion mechanism that converts a rotary motion of the injection motor 350 into a linear motion of the screw 330 or the like is provided between the injection motor 350 and the screw 330. The motion conversion mechanism includes, for example, a spindle shaft and a spindle nut screwed onto the spindle shaft. A ball, a roller or the like can be provided between the spindle shaft and the spindle nut. A driving source that causes the screw 330 to move back and forth is not limited to the injection motor 350 and may be, for example, a hydraulic cylinder.

The load detector 360 measures a load transmitted between the injection motor 350 and the screw 330. The measured load is converted into a pressure by the control device 700. The load detector 360 is provided in a load transfer channel between the injection motor 350 and the screw 330 and measures the load acting on the load detector 360.

The load detector 360 transmits a signal of the measured load to the control device 700. The load measured by the load detector 360 is converted into the pressure acting between the screw 330 and the molding material and becomes to control or monitor the pressure received by the screw 330 from the molding material , a back pressure against the screw 330, the pressure acting on the molding material by the screw 330 or the like.

A pressure detector for measuring the pressure of the molding material is not limited to the load detector 360, and a general detector can be used. For example, a nozzle pressure sensor or an internal mold pressure sensor can be used. The nozzle pressure sensor is installed in the nozzle 320. The mold internal pressure sensor is installed inside the mold unit 800.

The injection unit 300 performs a plasticizing process, a filling process, a pressurizing process, and the like under the control of the control device 700. The filling process and the pressurization process can be collectively referred to as an injection process.

In the plasticizing process, the plasticizing motor 340 is driven to rotate the screw 330 at a set speed so that the molding material is conveyed forward along the spiral groove of the screw 330. As a result, the molding material is gradually melted. When the liquid molding material is conveyed forward in front of the screw 330 and accumulates in a front portion of the cylinder 310, the screw 330 moves backward. The rotation speed of the screw 330 is measured, for example, by using a plasticizing motor encoder 341. The plasticizing motor encoder 341 measures the rotation of the plasticizing motor 340 and transmits a signal indicating a measurement result thereof to the controller 700. A screw speed detector for measuring the rotation speed of the screw 330 is not limited to the plasticizing motor encoder 341, and a general detector can be used.

In the plasticization process, the injection motor 350 may be driven to apply a set back pressure to the screw 330 to limit sudden retraction of the screw 330. The back pressure exerted on the screw 330 is measured, for example, by using the load detector 360. When the screw 330 moves backward to a plasticization completion position and a predetermined amount of molding material is accumulated in front of the screw 330, the plasticization process is completed.

The position and rotation speed of the screw 330 in the plasticizing process are collectively set as a series of setting conditions. For example, a plasticization start position, a speed switching position, and the plasticization completion position are set. These positions are arranged in this order from front to back and represent a starting point and an ending point of a section in which the rotation speed is set. The speed is set for each section. The number of speed switching positions can be one or more. It may be that the speed switching position is not set. In addition, the back pressure is set for each section.

In the filling process, the injection motor 350 is driven to cause the screw 330 to move forward at a set moving speed, and the cavity space 801 within the molding unit 800 is filled with the liquid molding material accumulated in front of the screw 330. The position or the moving speed of the screw 330 is measured, for example, by using an injection motor encoder 351. The injection motor encoder 351 measures the rotation of the injection motor 350 and transmits a signal indicating a measurement result thereof to the controller 700. When the position of the screw 330 reaches a set position, the filling process is switched to the pressure maintaining process (so-called V/P -Switch). The position at which V/P switching is performed is referred to as a V/P switching position. The set moving speed of the screw 330 can be changed in accordance with the position, a time, or the like of the screw 330.

The position and moving speed of the screw 330 in the filling process are collectively set as a series of setting conditions. For example, a filling start position (also referred to as an “injection start position”), the moving speed switching position and the V/P switching position are set. These positions are arranged in this order from back to front and represent the starting point and the ending point of the section in which the movement speed speed is set. The movement speed is set for each section. The number of moving speed switching positions may be one or more. The movement speed switching position may not be set.

For each section in which the moving speed of the screw 330 is set, an upper limit of the pressure of the screw 330 is set. The pressure of the screw 330 is measured by the load detector 360. In a case where the pressure of the screw 330 is equal to or lower than a set pressure, the screw 330 moves forward at a set moving speed. On the other hand, in a case where the pressure of the screw 330 exceeds the set pressure, in order to protect the mold, the screw 330 is caused to move forward at a lower moving speed than the set moving speed so that the pressure of the screw 330 is equal to or lower than is the set pressure.

After the position of the screw 330 reaches the V/P switching position in the filling process, the screw 330 may be temporarily stopped at the V/P switching position, and thereafter the V/P switching may be performed. Immediately before the V/P switching, instead of stopping the screw 330, the screw 330 may be caused to move forward at a low speed or it may be caused to move backward at a low speed. In addition, a screw position detector for measuring the position of the screw 330 and a screw moving speed detector for measuring the moving speed of the screw 330 are not limited to the injection motor encoder 351, and a general detector can be used.

In the pressure maintaining process, the injection motor 350 is driven to push the screw 330 forward. A pressure (hereinafter also referred to as a “holding pressure”) of the molding material in a front end portion of the screw 330 is maintained at a set pressure, and the molding material remaining within the cylinder 310 is pressed toward the molding unit 800. An insufficient amount of the molding material due to cooling shrinkage inside the molding unit 800 may be replenished. The holding pressure is measured, for example, by using the load detector 360. A set value of the holding pressure may be changed depending on an elapsed time since the start of the pressure holding process or the like. A plurality of holding pressures and a plurality of holding times for holding the holding pressures in the pressure holding process may be set respectively, or they may be set collectively as a series of setting conditions.

In the pressurizing process, the molding material in the cavity space 801 within the molding unit 800 is gradually cooled, and when the pressurizing process is completed, an inlet of the cavity space 801 is closed by the solidified molding material. This condition is referred to as a sprue seal and prevents the mold material from flowing back from the cavity space 801. After the pressure maintenance process, a cooling process starts. During the cooling process, the mold material is solidified within the cavity space 801. In order to shorten a molding cycle time, the plasticization process can be carried out during the cooling process.

The injection unit 300 of the present embodiment is of an in-line screw type, but may be of a pre-plasticized type. The pre-plasticizing type injection unit supplies the molding material melted within a plasticizing cylinder to an injection cylinder, and the molding material is injected into the molding unit from the injection cylinder. Inside the plasticizing cylinder, the screw is arranged so that it is rotatable and cannot move back and forth, or the screw is arranged so that it is rotatable and cannot move back and forth. On the other hand, a plunger is arranged to move back and forth inside the injection cylinder.

Furthermore, the injection unit 300 of the present embodiment is of a horizontal type in which the axial direction of the cylinder 310 is a horizontal direction, but may be of a vertical type in which the axial direction of the cylinder 310 is an up-down direction. The mold clamping/clamping unit combined with a vertical type injection unit 300 may be of the vertical type or the horizontal type. Similarly, the mold clamping/clamping unit combined with a horizontal type injection unit 300 may be of the horizontal type or the vertical type.

(movement unit)

When describing the movement unit 400, similarly to the description of the injection unit 300, a movement direction of the screw 330 during filling (e.g. the negative direction of the X-axis) is defined as forward, and a movement direction of the screw 330 during plasticizing (e.g positive direction of the X-axis) is defined as backwards.

The moving unit 400 causes the injection unit 300 to move back and forth with respect to the molding unit 800. The moving unit 400 presses the nozzle 320 against the mold unit 800, thereby generating a nozzle contact pressure. The moving unit 400 includes a hydraulic pump 410, a motor 420 serving as a driving source, a hydraulic cylinder 430 serving as a hydraulic actuator, and the like.

The hydraulic pump 410 has a first connection 411 and a second connection 412. The hydraulic pump 410 is a pump that can rotate in both directions and switches the rotation direction of the motor 420 so that a hydraulic fluid (for example, oil) is sucked from the first port 411 or the second port 412 and discharged from the other to generate hydraulic pressure. The hydraulic pump 410 may suck the hydraulic fluid from a tank, and may discharge the hydraulic fluid from the first port 411 or the second port 412.

The motor 420 drives the hydraulic pump 410. The motor 420 drives the hydraulic pump 410 in a rotation direction and with a torque in accordance with a control signal transmitted from the controller 700. The motor 420 may be an electric motor or may be an electric servo motor.

The hydraulic cylinder 430 has a cylinder body 431, a piston 432 and a piston rod 433. The cylinder body 431 is attached to the injection unit 300. The piston 432 divides the interior of the cylinder body 431 into a front chamber 435 serving as a first chamber and a rear chamber 436 serving as a second chamber. The piston rod 433 is attached to the stationary plate 110.

The front chamber 435 of the hydraulic cylinder 430 is connected to the first connection 411 of the hydraulic pump 410 via a first flow path 401. The hydraulic fluid discharged from the first port 411 is supplied to the front chamber 435 via the first flow path 401, thereby pushing the injection unit 300 forward. The injection unit 300 moves forward and the nozzle 320 is pressed against the stationary mold 810. The front chamber 435 functions as a pressure chamber that generates the nozzle contact pressure of the nozzle 320 using the pressure of the hydraulic fluid supplied from the hydraulic pump 410.

On the other hand, the rear chamber 436 of the hydraulic cylinder 430 is connected to the second port 412 of the hydraulic pump 410 via a second flow path 402. The hydraulic fluid discharged from the second port 412 is supplied to the rear chamber 436 of the hydraulic cylinder 430 via the second flow path 402, thereby pushing the injection unit 300 backward. The injection unit 300 moves backward and the nozzle 320 is separated from the stationary mold 810.

In the present embodiment, the moving unit 400 includes the hydraulic cylinder 430, but the present invention is not limited to this. For example, instead of the hydraulic cylinder 430, an electric motor and a motion conversion mechanism that converts a rotary motion of the electric motor into a linear motion of the injection unit 300 may be used.

(control device)

For example, the control device 700 is configured to include a computer and includes a central processing unit (CPU) 701, a storage medium 702 such as a memory, an input interface 703, and an output interface 704, as shown in FIG 1 and 2 shown. The control device 700 performs various types of controls by causing the CPU 701 to execute a program stored in the storage medium 702. In addition, the control device 700 receives a signal from the outside via the input interface 703 and transmits the signal to the outside via the output interface 704.

The control device 700 repeatedly performs the plasticizing process, the mold closing process, the pressurizing process, the mold closing/clamping process, the filling process, the pressure holding process, the cooling process, the pressure relief process, the mold opening process, the ejecting process, and the like, thereby repeatedly producing the molded product. A series of operations for obtaining the molded product, for example an operation from the start of the plasticization process to the start of the subsequent plasticization process, is referred to as a "shot" or a "molding cycle". In addition, a time required for a shot is referred to as a “mold cycle time” or a “cycle time”.

For example, a molding cycle includes the plasticizing process, the mold closing process, the pressurizing process, the mold closing/clamping process, the filling process, the pressure holding process, the cooling process, the pressure relief process, the mold opening process, and the ejection process in this order. The order described here is the order of the start times of the respective processes. The filling process, the pressure holding process and the cooling process are carried out during the mold closing/clamping process. The start of the mold closing/clamping process may coincide with the start of the filling process. The completion of the pressure relief process coincides with the start of the mold opening process.

Multiple processes can be carried out at the same time to shorten the molding cycle time. For example, the plasticization process may be performed during the cooling process of the previous molding cycle, or it may be performed during the mold closing/clamping process. In this case, the mold closing process can be carried out at an initial stage of the molding cycle. In addition, the filling process can start during the mold closing process. In addition, the ejection process can start during the mold opening process. In a case where an on-off valve for opening and closing the flow path of the nozzle 320 is provided, the mold opening process can start during the plasticizing process. The reason is as follows. Even if the mold opening process starts during the plasticizing process, the mold material does not come out from the nozzle 320 when the on-off valve closes the flow path of the nozzle 320.

A molding cycle may include a process other than the plasticizing process, the mold closing process, the pressurizing process, the mold closing/clamping process, the filling process, the pressure holding process, the cooling process, the pressure relief process, the mold opening process, and the ejection process.

For example, after the pressurization process is completed and before the plasticization process starts, a pre-plasticization suckback process may be performed by causing the screw 330 to move backward to a preset plasticization start position. The pressure of the molding material accumulated in front of the screw 330 can be reduced before the plasticization process starts, and a sudden withdrawal of the screw 330 when the plasticization process starts can be prevented.

Alternatively, after the plasticization process is completed and before the filling process starts, a post-plasticization suckback process may be performed by causing the screw 330 to move backwards to a preset filling start position. The pressure of the molding material accumulated in front of the screw 330 can be reduced before the filling process starts, and leakage of the molding material from the nozzle 320 can be prevented before the filling process starts.

The control device 700 is connected to an operation device 750 that receives an input operation from a user and with a display device 760 that displays a screen. For example, the operating device 750 and the display device 760 can be integrated with one another in the form of a touch panel 770. The touch panel 770, which serves as the display device 760, displays the screen under the control of the control device 700. For example, settings of the injection molding machine 10 and information regarding a current state of the injection molding machine 10 can be displayed on the screen of the touch panel 770. In addition, the screen of the touch panel 770 may display, for example, a button for accepting the user's input operation or an operation section such as an input field. The touch panel 770 serving as the operation device 750 detects an operation input of the user on the screen and outputs a signal corresponding to the operation input to the control device 700. In this way, while confirming information displayed on the screen, for example, the user can perform adjustment (including inputting a setting value) of the injection molding machine 10 by operating the operation section provided on the screen. Furthermore, the user can operate the injection molding machine 10 according to the operation section by operating the operation section provided on the screen. For example, the operation of the injection molding machine 10 may be an operation (including stopping) of the mold clamping/clamping unit 100, the ejector unit 200, the injection unit 300, the moving unit 400, or the like. Furthermore, the operation of the injection molding machine 10 can be performed by switching between the screens displayed on the touch panel 770 serving as the display device 760.

A case in which the operation device 750 and the display device 760 of the present embodiment are integrated with each other as the touch panel 770 has been described. However, these two can be provided independently. In addition, several of the operating devices 750 may be provided. The operation device 750 and the display device 760 are on the operation side (a negative direction of the Y axis) of the mold closing/clamping unit 100 (more particularly the stationary plate 110) is arranged.

(Details of control device)

Next, an example of components of the control device 700 will be described with reference to 3 described. Everyone in 3 The functional block shown is conceptual and may not necessarily be physically configured as shown. All or a portion of each functional block may be configured to be functionally or physically distributed and integrated into any unit. All or any portion of each processing function performed in each functional block may be implemented by a program executed by a CPU or may be implemented in hardware using hardwired logic.

As in 3 shown, the control device 700 includes, for example, a mold closing/clamping control unit 711, an ejector control unit 712, an injection control unit 713 and a plasticizing control unit 714. The mold closing/clamping control unit 711 controls the mold closing/clamping unit 100 to perform the mold closing process, the pressurizing process , to perform the mold closing/clamping process, the pressure relief process and the mold opening process, which in 4 to be shown. The ejector control unit 712 controls the ejector unit 200 to perform the ejecting process.

The injection control unit 713 controls the injection motor 350 of the injection unit 300 to perform the injection process and the cooling process. In addition, the injection process includes the filling process and the pressurizing process, and in the present embodiment, as shown in 4 shown, performed during the mold closing/clamping process. The filling process is a process in which the injection motor 350 is controlled so that an actual value of a moving speed of an injector provided inside the cylinder 310 becomes a set value. The filling process is a process in which the interior of the molding unit 800 is filled with the liquid molding material accumulated in front of the injection member by moving the injection member forward. The injection element is, for example, the screw 330 (see 1 and 2 ), but can also be a plunger.

The moving speed of the injector in the filling process is measured by using the injection motor encoder 351. In the filling process, since the pressure acting on the molding material increases as the injection member moves forward, a process of temporarily stopping the injection member or a process that causes the injection member to move backward may be included immediately before the pressure maintaining process.

The pressure maintaining process is a process in which a deficiency of the molding material due to cooling shrinkage in the molding unit 800 is replenished by pressing the injection member forward. In the pressure maintaining process, the injection motor 350 is controlled so that an actual value of a filling pressure becomes a setting value. The inflation pressure is measured using a pressure detector such as the load detector 360. As the pressure detector, a nozzle pressure sensor or a mold internal pressure sensor can be used.

Meanwhile, the plasticizing control unit 714 controls the plasticizing motor 340 of the injection unit 300 to perform the plasticizing process. In the present embodiment, the plasticization process is carried out during the cooling process. Furthermore, during the plasticizing process, the plasticizing control unit 714 reads a set temperature of each zone of the cylinder 310 and controls an operation of the heater (heating unit 313) based on the set temperature. Regarding heating control, the plasticizing control unit 714 maintains the set temperature by feeding back the temperature measured by each temperature measuring device 314.

(Cold start prevention control)

Next, cold start prevention control performed by the injection molding machine 10 will be described. After the machine is started, the injection molding machine 10 operates the heating unit 313 of each zone of the cylinder 310 to heat the cylinder 310 to melt the molding material to be filled into the molding unit 800. However, there is a time delay when the temperature of the mold material reaches a temperature of the cylinder 310. In particular, when the heating units 313 are started, there is a large temperature difference between them. Therefore, when the injection molding machine 10 is started, the injection control unit 713 performs the cold start prevention control to limit (lock) an operation of a plasticizing member (for example, a moving operation or a rotating operation of the screw 330) of the injection unit 300 until the temperature of the molding material the temperature of the cylinder 310 is reached in each zone. For example, the injection motor 350 is an example of a target of disabling, and the injection unit 300 cuts off power to the injection motor 350 using hardware or software. When the cold start prevention control reads the injection control unit 713 maintains a cold start prevention period stored in advance in the storage medium 702 and stops the rotation of the injection motor 350 during the cold start prevention period. A time at which the lock is applied to the mold closing/clamping unit 100 may be set as desired, and may be, for example, before the mold closing process is performed.

The cold start prevention period is time information during which the operation of the plasticizing member is limited, and an initial value (initial cold start prevention period) thereof is stored in advance in the storage medium 702 based on a configuration of the injection unit 300, a type of molding material, or the like. For example, the cold start prevention period may be set to 15 minutes. The initial value of the cold start prevention period may be entered by the user or may be automatically set by the injection molding machine 10 by acquiring information regarding the type of molding material.

Here, there are cases where the injection molding machine 10 is temporarily stopped during operation and then restarted. Examples of the temporary stop of operation include a power failure, an error in pressing an operation button by the user (operation error), an abnormal stop of the device, and a change in a set temperature of the device. In a case where the filling process is locked beyond the initial value of the cold start prevention period during this restart, the process cannot continue the filling process even if the temperature of the molding material reaches the temperature of the cylinder 310, and it takes time to do so to perform a restart. As a result, work efficiency decreases.

Therefore, in the injection molding machine 10 according to the present embodiment, when restarting after the operation is temporarily stopped, the cold start prevention period is appropriately adjusted to shorten the time required for the restart. Furthermore, even in a case where the set temperature of the cylinder 310 is increased during operation of the injection molding machine 10, a temperature difference occurs between the temperature of the cylinder 310 and the temperature of the molding material. Therefore, the injection molding machine 10 performs the cold start prevention control and the adjustment of the cold start prevention period even when the temperature rises due to the change in the set temperature of the cylinder 310.

In particular, as in 3 As shown, the control device 700 includes a period setting unit 715 configured to adjust the cold start prevention period. The period setting unit 715 detects the temperature measured by the temperature measuring device 314 in a predetermined zone of the cylinder 310 and stores the temperature in the storage medium 702. At this time, the period setting unit 715 generates temperature-time data TD in which the time measured by the control device 700 and the temperature stored in the storage medium 702 are associated with each other, and stores the temperature-time data TD in the storage medium 702.

5 is a diagram showing an example of the temperature-time data TD stored in the storage medium 702. As in 5 As shown, the temperature-time data TD has a one-to-one correspondence between the temperature measured by the temperature measuring device 314 during injection molding or the like and the measured time. For example, as described above, by using actual temperatures (individual data in which the temperature measured by the temperature measuring device 314 and time are linked), a temperature history can be tracked and analyzed, and the time at which an event such as a Abnormality occurs can be specified.

A temperature sampling interval is not particularly limited and may be set to, for example, every 10 seconds, every 30 seconds, every 1 minute, or every 3 minutes. The sampling interval may be a predetermined fixed value or may be changed by the user. The period setting unit 715 can automatically change the sampling interval according to the process of the injection molding machine 10 or the like.

Furthermore, the temperature measuring device 314 is not particularly limited in the target zone for storing the temperature, and for example, the front end portion (for example, the fourth zone) of the cylinder body 315 is more preferable. This is because the inside of the front end portion of the cylinder body 315 is a region where the molding material is in a molten state, and in a case where the molding material in this portion is insufficiently melted, a larger load than expected is applied , resulting in damage to the plasticizing member (a screw head of a tip of the screw 330, the backflow prevention ring 331, a three-piece set of a seat ring, the cylinder body 315, the nozzle 320 and the like). A configuration in which the period setting unit 715 the temperature of the temperature measuring device 314 is detected in the fourth zone.

While the injection unit 300 is in operation, the period setting unit 715 continuously samples the temperature of the temperature measuring device 314 and stores the temperature in the storage medium 702. Then, the period setting unit 715 performs the cold start prevention control in a case where the operation of the injection molding machine 10 is temporarily is stopped and then restarted in a case where the temperature of the cylinder 310 is increased in accordance with a change in the set temperature of the cylinder 310, or the like. At this time, the period setting unit 715 compares the actual temperature of the temperature-time data TD stored in the storage medium 702 before a predetermined time with the set temperature of the zone in which the temperature-time data TD is stored, and sets a length of the period setting unit 715 Cold start prevention period. The cold start prevention period setting includes, in addition to automatically adjusting the cold start prevention period via the controller 700, limiting an input range when the cold start prevention period is entered.

In addition, the control device 700 has a notification control unit 720, as in 3 shown. The notification control unit 720 causes the display device 760 to display various kinds of information regarding the operation of the injection molding machine 10 and image information such as an error when an abnormality occurs. In addition, the notification control unit 720 has a function of notifying the user of the information via the display device 760 in the case where the length of the cold start prevention period is adjusted. Accordingly, the user can easily recognize the adjusted cold start prevention period.

A process for adjusting the cold start prevention period will be described below with reference to 6 described. 6 is a flowchart showing a processing procedure for setting the cold start prevention period.

The injection molding machine 10 is started by an operation of the user to start the machine (step S1). With this start, the control device 700 is also started, and the CPU 701 executes the program stored in the storage medium 702, thereby enabling processing by the period setting unit 715.

The period setting unit 715 formed within the control device 700 determines whether or not a trigger condition for adjusting the cold start prevention period during operation of the injection molding machine 10 is established (step S2). For example, one of the following (a) to (c) is satisfied as the triggering condition.

1. (a) The heater (each heater unit 313) is changed from an OFF state to an ON state.
2. (b) A heater selection control is changed and a heater control is turned on.
3. (c) The set temperature of the heater is changed and the temperature of the heater is increased.

The trigger condition of (a) is a condition in which the operation of the heater is stopped when the operation is stopped, but also a heating operation of the heater is restarted when the operation is restarted. That is, in a case where the device is temporarily stopped and then restarted, the heater is switched from the OFF state to the ON state. This trigger condition is therefore met.

The heating selection control of the trigger condition of (b) means that any one of several modes for heating the cylinder 310 of the injection unit 300 is selected. Examples of the multiple modes include “Molding,” which is a temperature when injection molding is actually performed, “Heat Storage,” which is a temperature when waiting for injection molding, and “Cleaning,” which is a temperature when the molding material is disposed of. In a case where these modes are changed, there is a possibility that a difference occurs between the temperature of the cylinder 310 and the actual temperature of the molding material. Therefore, the injection control unit 713 performs the cold start prevention control and adjusts the cold start prevention period at this time.

In a case where it is necessary to increase the temperature of the cylinder 310 in response to a change in mode, the injection control unit 713 operates the heater to heat the cylinder 310. Examples of the case where it is necessary to increase the temperature of the cylinder 310 in response to a change in mode include a case where “Heat Storage” is changed to “Forming” and a case where “Cleaning” is changed to “heat storage” or “forming”. Since the actual temperature of the molding material does not immediately follow the temperature of the cylinder 310, a temperature difference. In contrast, in a case where it is necessary to lower the temperature of the cylinder 310 in response to a change in mode, the injection control unit 713 stops the heating operation of the heater to dissipate heat from the cylinder 310.

7 is a diagram showing a decision table of the trip condition in the heater selection control. In determining the trigger condition, the period setting unit 715 monitors a mode selection signal and a heating control (heating operation) signal with reference to the decision table as shown in 7 shown. Then, in a case where the mode selection is changed and the heating control is turned on, the period setting unit 715 sets a flag indicating that the trigger condition is established.

The trigger condition of (c) is a case where the set temperature of the heater (each heater unit 313) is changed at the user's request and the temperature of the heater is increased. Increasing the temperature of the heater means a state in which the temperature of the cylinder becomes equal to or higher than a predetermined difference after changing the setting. Even in this case, a difference occurs between the temperature of the cylinder 310 and the temperature of the molding material. Therefore, the period setting unit 715 performs the cold start prevention control and adjusts the cold start prevention period at this time.

That is, the trigger conditions of (b) and (c) are conditions for determining the temperature rise associated with the change in the set temperature of the cylinder 310. As described above, the period setting unit 715 also includes the case where the set temperature of the heating unit 313 is changed in the trigger condition, thereby adjusting the cold start prevention period in response to various situations where there is a difference between the temperature of the cylinder 310 and the temperature of the molding material, is adjusted appropriately.

Back to 6 , in a case where the above trip condition is established (YES in step S2), the period setting unit 715 proceeds to step S3, which is a processing flow for adjusting the cold start prevention period. On the other hand, in a case where the triggering condition is not established (NO in step S2), the period setting unit 715 repeats the determination in step S2 during the operation of injection molding or the like, thereby continuously monitoring the triggering condition. In the case where the triggering condition is established during the operation of injection molding or the like, the process then proceeds to step S3.

In step S3, the period setting unit 715 extracts an actual temperature Tz before a predetermined time from a time at which the trigger condition is established with reference to the temperature-time data TD stored in the storage medium 702, as data for determining whether the cold start Prevention period may or may not be shortened. As described above, the temperature-time data TD of the storage medium 702 is obtained by measuring the temperature of a predetermined zone (for example, the fourth zone) of the cylinder 310 via the temperature measuring device 314.

Furthermore, “before a predetermined time” to denote the extraction time in the temperature-time data TD is set to an appropriate value based on the time for the temperature of the molding material within the cylinder 310 to be sufficiently increased after the actual temperature of the cylinder 310 reaches the set temperature of the heating unit 313. This “before a predetermined time” is set in advance based on an experiment, simulation or experience, or at the user's request.

(2) $$\text{T}1\le \text{TG}<\text{T}2$$

(3) $$\text{T}2\le \text{TG}$$

Next, the period setting unit 715 compares the extracted actual temperature Tz before a predetermined time with the set temperature Ts for current temperature adjustment in the predetermined zone. In the temperature comparison, the period setting unit 715 calculates a temperature difference TG obtained by subtracting the actual temperature Tz before a predetermined time from a current set temperature Ts (step S4). Then, the period setting unit 715 determines which of a plurality of set temperature ranges and determination flags contains the calculated temperature difference TG (step S5). Examples of the multiple temperature ranges and determination flags include the following patterns.
(1) $$\text{TG}<\text{<figure-callout id="1" label="T" filenames="DE102023112151A1\_0010.png,DE102023112151A1\_0011.png" state="{{state}}">T</figure-callout>}1$$

(2) $$\text{<figure-callout id="1" label="T" filenames="DE102023112151A1\_0010.png,DE102023112151A1\_0011.png" state="{{state}}">T</figure-callout>}1\le \text{TG}<\text{<figure-callout id="2" label="T" filenames="DE102023112151A1\_0004.png,DE102023112151A1\_0005.png" state="{{state}}">T</figure-callout>}2$$

(3) $$\text{<figure-callout id="2" label="T" filenames="DE102023112151A1\_0004.png,DE102023112151A1\_0005.png" state="{{state}}">T</figure-callout>}2\le \text{TG}$$

T1 and T2 for specifying the temperature ranges correspond to predetermined temperature threshold values for determining the temperature difference TG. A relationship T1 < T2 is established between the temperature threshold T1 and the temperature threshold T2. Here, in a case where the temperature difference TG in (1) is smaller than T1, it can be said that the difference between the actual temperature Tz before a predetermined time and the set temperature Ts is small. Therefore, the period setting unit 715 sets determination 0 as the determination flag and performs processing of setting the cold start prevention period to zero. In a case where the temperature difference TG in (2) is T1 or larger and smaller than T2, it can be said that the difference between the actual temperature Tz before a predetermined time and the set temperature Ts is somewhat large. Therefore, the period setting unit 715 sets determination 1 as the determination flag and performs processing of shortening the cold start prevention period. A case where the temperature difference TG in (3) is T2 or larger, it can be said that the difference between the actual temperature Tz before a predetermined time and the set temperature Ts is sufficiently large. Therefore, the period setting unit 715 sets determination 2 as the determination flag and uses the initial value of the cold start prevention period as it is. In a case where there is no temperature-time data TD before a predetermined time in step S3, the period setting unit 715 cannot adjust the cold start prevention period. Therefore, in this case too, the period setting unit 715 sets determination 2 as the determination flag and uses the initial value of the cold start prevention period as it is.

When determination 0, determination 1 or determination 2 is determined in step S4, the period setting unit 715 sets the cold start prevention period based on this determination (step S6). The cold start prohibition period is a period during which the cold start prohibition control for locking the configuration (of the injection motor 350) of the injection molding machine 10 is performed. The period setting unit 715 allows the plasticizing member to operate when the period during which the lockout is performed reaches the cold start prevention period. For example, the period setting unit 715 does not apply the cold start prohibition period in the case of determination 0, sets the cold start prohibition period to a period (second period) shorter than the initial value in the case of determination 1, and maintains the cold start prohibition period. Prevention period at the initial value (first period) in the case of determination 2. The number of temperature ranges and determination flags for adjusting the cold start prevention period is not limited to three, but may be at least two. Accordingly, the first period can be set in the case where the temperature difference TG obtained by subtracting the actual temperature Tz a predetermined time ago from the current set temperature Ts is equal to or greater than the predetermined temperature threshold, and the second period can be set in the case where the temperature difference TG is smaller than the predetermined temperature threshold. Alternatively, the number of temperature ranges and determination flags can of course also be 4 or more.

Thereafter, the period setting unit 715 adjusts (changes or maintains) the cold start prevention period set at the initial value to the cold start prevention period set in step S6 (step S7). At this time, the injection molding machine 10 may be configured to automatically change the cold start prevention period in the period setting unit 715, or may be configured to notify the user of an input range of the cold start prevention period in which the setting is changed can, so that the user determines and changes the cold start prevention period based on the input range. In the case of automatically changing the cold start prevention period, the notification control unit 720 (see 3 ) Information from the period setting unit 715 and notifies the user of a setting state of the cold start prevention period. For example, the notification controller 720 changes a color of the cold start prevention period on a display screen of the display device 760, thereby visually notifying the user of the change. Accordingly, the user can easily recognize the period during which injection molding is blocked. Alternatively, the notification controller 720 may generate a pop-up screen on the display screen, or may notify of the change by turning on an alarm tone, sound output, lamp, or the like. Furthermore, in the case where the user makes the determination, notification of information indicating that the cold start prevention period may be changed may be sent, and thereafter, after the cold start prevention period is changed by the user, notification may be sent about information indicating that the setting of the cold start prevention period is completed.

Then, the injection control unit 713 performs the cold start prevention control based on the cold start prevention period set in the period setting unit 715 (step S8). Old Natively, in the case where the cold start prohibition period is zero, the injection control unit 713 does not perform cold start prohibition control.

The injection control unit 713 performs inhibition for the cold start prohibition period set in the cold start prohibition control and thereafter allows the operation of the plasticizing member (step S9). Accordingly, the injection molding machine 10 can perform the user-set operation (the filling process, cleaning including the plasticizing process, the molding mode, and the like) immediately after the cold start prevention control is performed. For example, the injection control unit 713 starts a cleaning operation after the operation of the plasticizing member is permitted. Accordingly, the injection unit 300 can stably mold the molded product without applying a large load to the plasticizing member or the molding unit 800.

In a case where data of the actual temperature Tz before a predetermined time is not present in the temperature-time data TD stored in the storage medium 702, the injection control unit 713 may calculate the actual temperature Tz before a predetermined time by using temperature Time data TD used before and after the predetermined time. Examples of the case where data of the actual temperature Tz is not present before a predetermined time include a stop of operation of the device (including a power failure), a temporary failure of the temperature measuring device, a communication function, and the like.

8A and 8B are diagrams for describing interpolation of the temperature-time data TD, where 8A is a table representing the temperature-time data TD, and 8B is a graph of 8A . As in 8A and 8B are shown when the injection control unit 713 reads a temperature before a predetermined time in the temperature-time data TD stored in the storage medium 702 to adjust the cold start prevention period in a case where the actual temperature Tz before a predetermined time is not present (empty), read temperatures and times before and after the empty period. Then, the injection control unit 713 linearly interpolates a temperature in the idle period based on the temperature immediately before the idle period and the temperature immediately after the idle period.

In the example of 8A and 8B After the power of the injection molding machine 10 was turned off at 4:04 p.m., the power of the injection molding machine 10 was turned on at 4:13 p.m. Therefore, there is a blank period where there is no temperature information from 16:04 to 16:13. Then, at 4:21 p.m., the injection control unit 713 determines the adjustment of the cold start prevention period. In determining the cold start prevention period, there is no temperature information even if an attempt is made to extract the actual temperature Tz 15 minutes ago (16:06) as a predetermined time.

Therefore, at 4:03 p.m., the injection control unit 713 extracts a temperature (250°C) which is the temperature measured immediately before the power is turned off, and at 4:14 p.m. a temperature (195°C) which is the is the temperature detected immediately after the power is turned on. The injection control unit 713 calculates an imaginary line of a temperature that linearly decreases based on the period from 16:03 to 16:14 and on the two temperatures, 250 ° C and 195 ° C. Then, the injection control unit 713 extracts 235°C, which is the temperature at 4:06 p.m., based on the calculated imaginary line.

As described above, even in a case where the actual temperature Tz before a predetermined time is not present in the storage medium 702, the injection control unit 713 can smoothly and accurately obtain a temperature sufficiently close to the actual temperature Tz before a predetermined time , by interpolating the empty period temperature without the actual temperature Tz. The injection molding machine 10 can satisfactorily adjust the cold start prevention period by using the actual temperature Tz before a predetermined time.

As described above, in the injection molding machine 10 according to the present embodiment, in a case where there is a difference between the temperature of the cylinder 310 and the temperature of the molding material, the cold start prevention period, which is a period for limiting the operation of the plasticizing member (for example, the moving operation or the rotating operation of the screw 330) can be easily and appropriately adjusted by the period setting unit 715. For example, in a case where the operation of the injection molding machine 10 is temporarily stopped due to a power failure, an operation error, or the like and then restarted at a stage where the temperature of the cylinder 310 does not decrease sharply, the period setting unit 715 shortens the cold start time. prevention period. Accordingly, the injection molding machine 10 can shorten the time required to fill the molding material while protecting the plasticizing member such as the screw 330. This allows the spray casting machine 10 can be restored early despite the device stopping for a short period of time, and the amount of molding material consumed at the time of starting can be reduced.

In addition, the period setting unit 715 can easily adjust the cold start prevention period by comparing the past actual temperature Tz with the set temperature of the heating unit 313. In this comparison, the period setting unit 715 can set a more optimal cold start prevention period by using the temperature difference TG obtained by subtracting the past actual temperature Tz from the current set temperature Ts. Further, in a case where the past actual temperature Tz is close to the set temperature, the injection molding machine 10 can further shorten the filling of the molding unit 800 with the molding material by shortening the cold start prevention period.

The injection molding machine 10 includes the temperature measuring device 314 for adjusting the cold start prevention period in the front end portion of the cylinder 310 so that a state of the molding material in the front end portion of the cylinder 310 in which a load is lightly applied to the plasticizing member can be easily monitored .

The injection molding machine 10 and the control device 700 of the injection molding machine 10 according to the embodiment of the present invention are not limited to the embodiment, and various modification examples can be applied. For example, the injection molding machine 10 is not limited to installing the temperature gauge 314 in the cylinder 310, and may be configured to measure the temperature of the mold unit 800 via the temperature gauge installed in the mold unit 800 (the stationary mold 810 or the like). When the molding material is injected into the mold from the injection molding machine in a state where the temperature of the molding unit 800 is not within the set temperature range, there is a possibility that the mold has a poor filling condition, for example, that the mold is pitted, the molded product is not released from the mold or that burrs are created. Particularly, in a case where the injection molding machine performs thermal curing (reaction molding), there are problems in that the molding material does not solidify normally, functional performance required for the molded product cannot be obtained, and the like. Therefore, by measuring the temperature of the molding unit 800, setting the cold start prevention period based on the temperature of the molding unit 800, and limiting one or more of the operations of the molding unit 800 or the operation of the plasticizing member, the poor filling condition can be permanently suppressed.

In this case, the temperature control mechanism of the molding unit 800 is not limited to the heater and may have a configuration in which a temperature control medium circulates between a temperature control medium circulation device (not shown) and the molding unit 800. The configuration in which the temperature control medium is circulated can be applied to the cylinder 310.

In the case of the configuration in which the temperature control medium is circulated, in the injection molding machine 10, the cylinder 310 may be cooled by the temperature control medium supplied to the cylinder 310 when the actual temperature Tz stored in the storage medium 702 is higher than the set temperature before a predetermined time is. In addition, the injection molding machine 10 may disable the operation of the device during this period or may set the disable period based on the current temperature Tz.

In the embodiment, the period setting unit 715 sets the cold start prevention period associated with the plurality of temperature ranges and the determination flags by using the temperature difference TG. However, the period setting unit 715 can, for example, linearly change the cold start prevention period by using a mathematical expression in which the temperature difference TG and the cold start prevention period are related to each other.

The injection molding machine 10 and the control device 700 of the injection molding machine 10 according to the embodiment disclosed herein are in all respects exemplary and are not limiting. The embodiment may be modified and improved in various forms without departing from the scope of the claims and their spirit. Items described in the multiple embodiments may have other configurations within a consistent range and may be combined within a consistent range.

Brief description of the reference numbers

10

Injection molding machine

310

cylinder

313

Heating unit (temperature control mechanism)

314

Temperature measuring device

700

Control device

715

Period setting unit

800

Form unit

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP H11170327 [0004, 0005]

Claims (11)

Injection molding machine (10), comprising: a cylinder (310) holding a molding material to be injected into a mold; a plasticizing member provided in the cylinder (310) so as to be movable and rotatable; a temperature measuring device (314) that measures a temperature of the cylinder (310) or the mold; and a period setting unit (715) configured to set a cold start prevention period, which is a period for limiting an operation of the plasticizing member until a temperature of the molding material or the temperature of the mold increases, wherein the period setting unit (715) stores temperature-time data (TD) in which the temperature measured by the temperature measuring device (314) is linked to time, and the cold start prevention period based on an actual temperature (Tz) of the stored temperature-time -Data (TD) sets. Injection molding machine (10). Claim 1 , wherein the period setting unit (715) compares the actual temperature (Tz) before a predetermined time with a set temperature (Ts) of a temperature control mechanism (313) that adjusts a current temperature of the cylinder (310) or the mold. Injection molding machine (10). Claim 2 , wherein the period setting unit (715) has, as the cold start prevention period, a first period and a second period shorter than the first period in advance, sets the first period in a case where a temperature difference (TG) caused by Subtracting the actual temperature (Tz) obtained before a predetermined time from a current set temperature (Ts) of the temperature control mechanism (313) is equal to or greater than a predetermined temperature threshold, and sets the second period in a case where the temperature difference ( TG) is smaller than the predetermined temperature threshold. Injection molding machine (10). Claim 2 or 3 , wherein the period setting unit (715) sets zero as the cold start prevention period in a case where a temperature difference (TG) obtained by subtracting the actual temperature (Tz) before a predetermined time from a current set temperature (Ts) of the temperature control mechanism ( 313) is obtained falls within a permissible range. Injection molding machine (10). Claim 2 or 3 , wherein in a case where the actual temperature (Tz) is not present before a predetermined time, the period setting unit (715) makes a temperature change based on the actual temperature (Tz) before and after a period in which the actual temperature (Tz ) is not present, interpolated. Injection molding machine (10). Claim 2 or 3 , wherein the period setting unit (715) adjusts the cold start prevention period based on establishment of a trigger condition, and the trigger condition includes a case in which the temperature control mechanism (313) is switched from an OFF state to an ON state. Injection molding machine (10). Claim 6 , wherein the trigger condition includes a case where the set temperature (Ts) of the temperature control mechanism (313) is changed and the temperature control mechanism (313) is in the ON state. Injection molding machine (10) according to one of the Claims 1 until 3 , wherein the cylinder (310) has a cylinder body (315) that heats the molding material and a nozzle (320) that injects the molding material heated by the cylinder body (315) into the mold in front of the nozzle (320), and that Temperature measuring device (314) is provided at a front end portion of the cylinder body (315). Injection molding machine (10) according to one of the Claims 1 until 3 , further comprising: a notification control unit (720) configured to notify a user of information about changing the setting of the cold start prevention period via the period setting unit (715) or information about limiting an input range. Control device (700) of an injection molding machine (10), in which the control device (700) enables a temperature measuring device (314) to measure a temperature of a cylinder (310) which holds a molding material to be injected into a mold, or a temperature of the mold, and enabling a temperature control mechanism (313) to adjust the temperature of the cylinder (310) or the mold based on the temperature measured by the temperature measuring device (314), the control device (700) comprising: a period setting unit (715) so configured that it sets a cold start prevention period, which is a period for limiting an operation of a plasticizing member provided in the cylinder (310) so that it is movable and rotatable until a temperature of the molding material or the temperature of the mold increases, the period setting unit (715) storing temperature-time data (TD) in which the temperature measured by the temperature measuring device (314) is linked to time and sets the cold start prevention period based on an actual temperature (Tz) of the stored temperature-time data (TD). Control device (700) of an injection molding machine (10). Claim 10 , further comprising: a notification control unit (720) configured to notify a user of information about changing the setting of the cold start prevention period via the period setting unit (715) or information about limiting an input range.

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